#! /usr/bin/env python
#
#  Copyright (c) 2013, The Linux Foundation. All rights reserved.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions are
#  met:
#      * Redistributions of source code must retain the above copyright
#        notice, this list of conditions and the following disclaimer.
#      * Redistributions in binary form must reproduce the above
#        copyright notice, this list of conditions and the following
#        disclaimer in the documentation and/or other materials provided
#        with the distribution.
#      * Neither the name of The Linux Foundation nor the names of its
#        contributors may be used to endorse or promote products derived
#        from this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
#  ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
#  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
#  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
#  OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
#  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# Drop in replacement for android's mkbootimg plus some more additions
#

from struct import pack
import os
from optparse import OptionParser

def write_padding(f, pagesize):
	count = pagesize - (f.tell() % pagesize)
	# Write padding as long as we aren't already aligned to a page
	if count != pagesize:
		output.write(b'\x00' * count)

if __name__ == "__main__":
	usage = ("""%prog [options]""")
	parser = OptionParser(usage=usage)
	# Standard options
	parser.add_option("--kernel", dest="kernel", metavar="FILE",
			  help="Input kernel image")
	parser.add_option("--ramdisk", dest="ramdisk", metavar="FILE",
			  help="Input ramdisk image")
	parser.add_option("--base", type="int", dest="base",
			  help="Start address of kernel image")
	parser.add_option("--output", dest="output", metavar="FILE",
			  help="Write output to FILE")
	parser.add_option("--cmdline", dest="cmdline",
			  help="Kernel command line")
	parser.add_option("--pagesize", type="int", dest="pagesize",
			  default=2048,
			  help="NAND pagesize [default: %default]")
	# New options
	parser.add_option("--ramdisk_base", type="int", dest="ramdisk_base",
			  default=-1, help="Start address of ramdisk image")
	parser.add_option("--dt", dest="devicetree", metavar="FILE",
			  help="Input device tree image")

	(options, args) = parser.parse_args()

	if options.kernel is None:
		parser.error("Must specify --kernel")
	if options.ramdisk is None:
		parser.error("Must specify --ramdisk")
	if options.output is None:
		parser.error("Must specify --output")
	if options.base is None:
		parser.error("Must specify --base")
	if options.cmdline is None:
		parser.error("Must specify --cmdline")

	try:
		kernel = open(options.kernel, 'rb')
	except IOError:
		exit("Can't open %s" % options.kernel)
	try:
		ramdisk = open(options.ramdisk, 'rb')
	except IOError:
		exit("Can't open %s" % options.ramdisk)
	try:
		output = open(options.output, 'wb')
	except IOError:
		exit("Can't open %s" % options.output)
	if options.devicetree:
		try:
			devicetree = open(options.devicetree, 'rb')
		except IOError:
			exit("Can't open %s" % options.devicetree)

	pagesize = options.pagesize
	tags = options.base + 0x100
	ramdisk_base = options.ramdisk_base if options.ramdisk_base != -1 else options.base + 0x2000000

	kernel_size = os.fstat(kernel.fileno()).st_size
	dtb_size = 0
	if options.devicetree:
		magic = devicetree.read(4)
		devicetree.seek(0)
		if magic == b'\xd0\x0d\xfe\xed': # 0xd00dfeed
			append_dtb = True
			kernel_size += os.fstat(devicetree.fileno()).st_size
		elif magic == b'QCDT':
			append_dtb = False
			dtb_size = os.fstat(devicetree.fileno()).st_size
		else:
			exit("dtb: %s is of unknown format" % options.devicetree)

	hdr_format = "<8sIIIIIIII2I16s512s8I"
	output.write(pack(hdr_format,
			  b"ANDROID!",
			  kernel_size,
			  options.base + 0x8000,
			  os.fstat(ramdisk.fileno()).st_size,
			  ramdisk_base,
			  0, 0,
			  tags,
			  options.pagesize,
			  dtb_size, 0,
			  b"",
			  options.cmdline.encode(),
			  123456, 123456, 123456, 123456, 123456, 123456,
			  0, 0))
	write_padding(output, pagesize)
	output.write(kernel.read())
	if options.devicetree and append_dtb:
		output.write(devicetree.read())
	write_padding(output, pagesize)
	output.write(ramdisk.read())
	write_padding(output, pagesize)
	if options.devicetree and not append_dtb:
		output.write(devicetree.read())
	write_padding(output, pagesize)
